Extech MN47 Operating Manual

User's Guide

Autoranging Multimeter

Model MN47

Introduction

Congratulations on your purchase of the MN47 MultiMeter. The MN47 offers AC/DC Voltage,
AC/DC Current, Resistance, Diode, and Continuity and Temperature. Proper use and care of
this meter will provide many years of reliable service.

Safety

This symbol adjacent to another symbol, terminal or operating device
indicates that the operator must refer to an explanation in the Operating
Instructions to avoid personal injury or damage to the meter.

WARNING

CAUTION

MAX
600V

SAFETY INSTRUCTIONS

This meter has been designed for safe use, but must be operated with caution. The rules
listed below must be carefully followed for safe operation.

1. NEVER apply voltage or current to the meter that exceeds the specified maximum:

Function Maximum Input

V DC or V AC 600V AC and DC

mA AC/DC 400mA DC/AC

A AC/DC 10A DC/AC (for 30 seconds max. every 15 minutes

Frequency, Resistance,
Capacitance, Duty Cycle, Diode,
Continuity, Temperature

2. USE EXTREME CAUTION when working with high voltages.

3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above earth ground.

4. NEVER connect the meter leads across a voltage source while the function switch is in the current,

resistance, or diode mode. Doing so can damage the meter.

5. ALWAYS discharge filter capacitors in power supplies and disconnect the power when making resistance

or diode tests.

6. ALWAYS turn off power and disconnect test leads before opening the covers to replace the fuse or battery.

7. NEVER operate the meter unless the back cover and the battery and fuse covers are in place and fastened

securely.

8. DO NOT use the meter if the meter or test leads look damaged, or if you suspect the meter is not operating

properly.

9. If the equipment is used in a manner not specified by the manufacturer, the protection provided by the
equipment may be impaired.

This WARNING symbol indicates a potentially hazardous situation, which
if not avoided, could result in death or serious injury.

This CAUTION symbol indicates a potentially hazardous situation, which
if not avoided, may result damage to the product.

This symbol advises the user that the terminal(s) so marked must not be
connected to a circuit point at which the voltage with respect to earth
ground exceeds 600V.

This symbol adjacent to one or more terminals identifies them as being
associated with ranges that may, in normal use, be subjected to
particularly hazardous voltages. For maximum safety, the meter and its
test leads should not be handled when these terminals are energized.

Input Protection Limits

250V DC/AC

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Controls and Jacks

1. Non-Contact AC voltage tester

2. 4000 count LCD display

3. RANGE button

4. MODE button

5. HOLD button

6. RELATIVE button

7. Function switch

8. COM (negative) input jack

9. Positive 10A input jack

10. Positive input jack

Symbols and Annunciators

•))) Continuity

Diode test

+

Low battery

HOLD Data hold

Auto Autoranging

AC Alternating current

DC Direct current

REL Relative

µ micro (amps)

m milli (volts, amps)

k kilo (ohms)

Ω Ohms

1

2

3

4

7

8

9

5

6

10

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OPERATING INSTRUCTIONS

WARNING: Risk of electrocution. High-voltage circuits, both AC and DC, are very
dangerous and should be measured with great care.

1. ALWAYS turn the function switch to the OFF position when the meter is not in use.

2. If OL appears in the display, the value exceeds the range you have selected. Change

to a higher range.

NOTE: On some low AC and DC voltage ranges, with the test leads not connected to a
device, the display may show a random, changing reading. This is normal and is caused
by the high-input sensitivity. The reading will stabilize and give a proper measurement
when connected to a circuit.

RANGE BUTTON

When the meter is first turned on, it automatically goes into autoranging mode. To manually

select the range to be tested perform the following.

1. Press RANGE button. The AUTO display will turn off.

2. Press RANGE button to step through the available ranges.

3. Press and hold the RANGE button for 2 seconds to exit the manual ranging mode

and return to autoranging.

NOTE: Manual ranging does not apply for Capacitance, Frequency, Diode, Continuity and

Duty Cycle.

DATA HOLD BUTTON

Data hold allows the meter to “freeze” a measurement in the display.

1. Press DATA HOLD button to “freeze” the reading on the LCD. The indicator “HOLD”

will appear on the display.

2. Press DATA HOLD button to return to normal operation

RELATIVE BUTTON

The relative measurement feature allows you to make measurements relative to a stored
reference value. A reference voltage, current, etc. can be stored and measurements made in
comparison to that value. The displayed value is the difference between the reference value
and the measured value.

1. Perform any measurement as described in operating instructions.

2. Press the RELATIVE button to store the reading in the display and the REL indicator

will appear on the display.

3. The display will now indicate the difference between the stored value and measured

value.

4. Press the RELATIVE button to return to normal operation.

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NON-CONTACT AC VOLTAGE DETECTOR

WARNING: Always test the NCV function on a know live circuit before use

1. Turn the rotary switch to any measurement position

2. Hold the top of the meter very close to the voltage source as shown.

3. If voltage is present, the LED above the display will glow and the

meter will buzz.

NOTE: The detector is designed with high sensitivity. Static electricity or
other sources of energy may randomly trip the sensor. This is normal
operation.

AC VOLTAGE MEASUREMENTS

WARNING: Risk of Electrocution. The probe tips may not be long enough to contact the

live parts inside some 240V outlets for appliances because the contacts are recessed
deep in the outlets. As a result, the reading may show 0 volts when the outlet actually has
voltage on it. Make sure the probe tips are touching the metal contacts inside the outlet
before assuming that no voltage is present.

CAUTION: Do not measure AC voltages if a motor on the circuit is being switched ON or
OFF. Large voltage surges may occur that can damage the meter.

1. Set the function switch to the VAC position.

2. Insert the black test lead banana plug into the negative COM jack.

Insert the red test lead banana plug into the positive V jack.

3. Touch the black test probe tip to the neutral side of the circuit.

4. Touch the red test probe tip to the “hot” side of circuit.

5. Read the voltage in the display.

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